1. Field of the Invention
The present invention relates to an ink-jet recording apparatus which includes an ink-jet head performing a recording by discharging (jetting) an ink onto a recording-objective medium by drive of an actuator, and which determines a drive voltage of the actuator according to a temperature of the ink, and a recording method by using the ink-jet recording apparatus.
2. Description of the Related Art
As an ink-jet recording apparatus of such a type, there has hitherto known an apparatus described, for example, in Japanese Patent Application Laid-open No. 06-008049 (corresponding to U.S. Pat. Nos. 4,860,034, 5,172,142 and 5,905,511), which determines, when performing recording on a plurality of sheets of recording paper, a drive voltage according to a temperature of a head (head temperature) every time the recording is started on each of the recording papers. FIG. 8 is a graph showing a relationship, in such an ink-jet recording apparatus, between the head temperature and the drive voltage when the recording was performed at 50% recording duty. In the first recording paper, the head temperature at the start of recording is 21° C., and the drive voltage is set to 24.5 V. Further, the recording is performed at the same 24.5 V without changing the drive voltage until the recording of the first recording paper is completed. Further, for a second recording paper and a third recording paper, the recording is performed at the drive voltage of 23.0 V and 22.5 V, respectively.
On the other hand, in an ink-jet recording apparatus in which a driving IC chip (integrated circuit ship) which outputs a driving signal to an actuator is mounted on an ink-jet head, as the IC chip and the actuator generate heat due to a recording operation, the generated heat is transmitted to an ink in the ink-jet head, and there is a rise in a temperature of the ink (ink temperature). Further, as a recording density is increased, amount of heat generated by the IC chip and the actuator is increased accompanying thereto; and as the amount of generated heat is increased, the temperature of the ink also rises accompanying thereto. In such case, in order to deal with a decrease in the ink viscosity accompanying the rise in the temperature of the ink, it is necessary to lower (decrease) the drive voltage. However, in the conventional ink-jet recording apparatus as described above, even when the ink temperature is changed for a period of time during which the recording is performed on one page of the recording paper, the recording is performed at the same drive voltage. Therefore, it is not possible to perform a recording corresponding to the viscosity of ink, and thus there is a problem that recording quality is declined. In particular, in case in which an image or the like having an extremely high density of recording is recorded right away, such as performing recording of a photo data immediately after the power supply is turned ON, it is conceived that the temperature of the ink is raised suddenly, and there is a fear that the decline in the recording quality is prominent or conspicuous. Further, these days, the ink-jet printers are used all over the world and it is necessary that the ink-jet printers are adjusted to any sort of environment in which the printers are used. In particular, it is necessary that the ink-jet printers are adjusted to a sudden change in the environment in which the ink-jet printers are used when the user starts to use the printer or during the printer is being used.